Formatting codes not working in 1.14

Formatting codes are not working at all with Book&Quill.

Reproduce:

1. Create a new creative world in 1.14

2. Get a book&quill

3. Paste

§nXXX

Expected: XXX (with underlines).
Result: XXX (without underlines, see image).

 The same procedure is working in 1.13.2